xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/divti3.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- divti3.c - Implement __divti3 -------------------------------------===//
2*0b57cec5SDimitry Andric //
3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric //
7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric //
9*0b57cec5SDimitry Andric // This file implements __divti3 for the compiler_rt library.
10*0b57cec5SDimitry Andric //
11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
12*0b57cec5SDimitry Andric 
13*0b57cec5SDimitry Andric #include "int_lib.h"
14*0b57cec5SDimitry Andric 
15*0b57cec5SDimitry Andric #ifdef CRT_HAS_128BIT
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric // Returns: a / b
18*0b57cec5SDimitry Andric 
19*0b57cec5SDimitry Andric COMPILER_RT_ABI ti_int __divti3(ti_int a, ti_int b) {
20*0b57cec5SDimitry Andric   const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1;
21*0b57cec5SDimitry Andric   ti_int s_a = a >> bits_in_tword_m1;                   // s_a = a < 0 ? -1 : 0
22*0b57cec5SDimitry Andric   ti_int s_b = b >> bits_in_tword_m1;                   // s_b = b < 0 ? -1 : 0
23*0b57cec5SDimitry Andric   a = (a ^ s_a) - s_a;                                  // negate if s_a == -1
24*0b57cec5SDimitry Andric   b = (b ^ s_b) - s_b;                                  // negate if s_b == -1
25*0b57cec5SDimitry Andric   s_a ^= s_b;                                           // sign of quotient
26*0b57cec5SDimitry Andric   return (__udivmodti4(a, b, (tu_int *)0) ^ s_a) - s_a; // negate if s_a == -1
27*0b57cec5SDimitry Andric }
28*0b57cec5SDimitry Andric 
29*0b57cec5SDimitry Andric #endif // CRT_HAS_128BIT
30